The need for rapid detection is important for with many conventional technologies by the time the poison has been identified, the damage to an individual may have already taken place. With this, the inventors of the new device, who are based at Floris van den Brink of the University of Twente, cite the example of polycyclic aromatic hydrocarbons. These chemicals, found in asphalt can rapidly harm a person because they interact with hemoglobin in blood.
The new device is modeled on the human liver. In the way that the liver converts different substances into metabolites, so the lab-on-a-chip breaks down a potential toxin and the identification of the breakdown products can be conducted more speedily than is possible with the intact toxic compound.
This works through the application of a tiny electrochemical reactor and by running a series of nano-scale fluid reactions. The reactor generates PAH metabolites, such as hydroxypyrene. These metabolites are then mixed with hemoglobine. This enables a chemist to see which toxic and highly reactive metabolites bind to hemoglobin. The result is obtained in less than one second, measured by diamond electrodes. Analysis stakes place by mass spectrometry.
The chip has a second function. It allows a medic to assess which medications might help to neutralize the toxin. This is a far faster process than testing out different antidotes on laboratory animals.
In developing the device, the most complex activity involved producing the mixing chambers. For this, two mixing chambers were developed made up of tiny channels that have a gradient. The gradient allows a substance to enter the chamber above and the other below. The use of different gradients allows mixing to take place rapidly.
A further application with the technology could be with protein analysis, and this could aid the development of medicines.
The research has been published in the journal Chemistry, in a paper titled “Oxidation and adduct formation of xenobiotics in a microfluidic electrochemical cell with boron doped diamond electrodes and an integrated passive gradient mixer.”
